The use of organic solvents, thinners and cleaners is important to many industrial and commercial processes. One example is the use of organic solvents to clean and degrease metal components such as engine and other motor vehicle parts. Another example is dry cleaning processes in which fabrics are cleaned by applying synthetic and petroleum solvents to remove greasy soils. In each of these processes, the components or fabrics to be cleaned are subjected to the action of one or more solvents to remove grease, oil, and the like. Since the grease and oil are dissolved into the solvent, the solvent that remains is contaminated. Many such solvents are classified as hazardous waste. Consequently they cannot be disposed of through conventional means. Commercial solvents themselves are relatively expensive. Added to this expense are increasingly strict management requirements and regulations.
The economics and benefits of in-house solvent recycling systems are becoming increasingly apparent. As a result, a variety of systems for on-site solvent purification and recovery have been developed.
While the systems of the prior art have been effective in recovering solvent, some problems associated with solvent recovery processes have yet to be overcome. These problems stem from the toxic nature of the solvents being processed and the high temperatures required to heat the contaminated solvents to their boiling points. In particular the surfaces surrounding the heating and boiling elements of such systems become extremely hot and pose dangers to an operator. Additionally, noxious fumes emitted during the process can escape into the atmosphere presenting further operator and environmental hazards. Of further concern to the operator is the amount of system information readily available to her during system operation and the ease with which the operator can determine the status of the system.
Representative U.S. Pat. No. 4,929,312 to Westcott discloses a solvent recovery apparatus and method comprising an evaporator unit having a heat source for vaporizing solvent from a contaminated body of such solvent. This earlier device lacks desired features for preventing organic solvent from escaping into the atmosphere.
Accordingly, there is a need for an improved, highly automated, plug-in ready to use system for purifying organic solvents for recycling and reuse while providing important operational safety features, and which is unitized into an integral, highly compact device especially useful for shops and plants having limited floor space.